M. W. Rowe

• Ph.D. Chemistry
• Texas A&M University

We successfully measured four radiocarbon dates on two specimens of a black geometric rock painting with a fragment in jeopardy of naturally spalling off in the wall of a rock shelter in the Ẓufār region, in the south of the Sultanate of Oman. Extraction of carbon dioxide (CO 2 ) for radiocarbon dating of the binder in the black pigment of the rock...

At Lowry Pueblo, small fragments of painted plaster are all that remain of a bold white step pattern mural that once decorated Kivas A and B. We used the following analytical techniques to study these fragments: visual microscopic analysis, portable X-ray fluorescence, scanning electron microscopy with an energy dispersive X-ray spectrometer, powde...

Plasma oxidation for ¹⁴ C sampling utilizes low-pressure (133 Pa), low-energy (<50 W), and low- temperature (<50°C) Ar- and O 2 -plasmas generating CO 2 for AMS dating. O 2 -plasmas on empty chambers remove organic contamination. When clean, a new specimen is inserted and Ar-plasmas dislodge adsorbed atmospheric CO 2 from surfaces. Finally, O 2 -pl...

An early 1980s University of Texas (UT) radiocarbon (¹⁴C) decay-based assay of colon contents from mummy SMM recovered from southwest Texas (41VV656) placed the death at 1150 ± 70 ¹⁴C years ago. This mummy of a “relatively tall, gracile adult male” was discussed in some detail in a comprehensive paper on Late Archaic mortuary practices in the Lower...

At Serpentine Bends Site #1, we employed plasma oxidation followed by accelerator mass spectrometry to radiocarbon date two prehistoric rock paintings as well as soot on the shelter ceiling. Pictograph results are 2325 ± 30 ¹⁴C years BP for a black line and 1315 ± 40 ¹⁴C years BP for a red outline of a circle motif. We also utilized X-ray diffracti...

Pigment analysis of rock paintings

Dating rock paintings

Se cuestiona la adscripción contemporánea de la figura de estilo paleolítico existente en El Portalón de Cueva Mayor, dentro del complejo kárstico de la Sierra de Atapuerca en Burgos. Se plantea una revisión crítica de los argumentos utilizados en un estudio anterior y se valoran nuevas evidencias y datos disponibles desde entonces. Las conclusione...

Wyoming State Parks recovered a large chunk of the Medicine Lodge Creek Archaeological Site cliff wall, which had fallen away, with rock paintings on it. A sample from one of the paintings was dated to 800 BP with the Plasma Oxidation dating method. Comparison to regional sites suggests the dated painting is part of the Foothills Abstract tradition...

W ithin the dark zone of Picture Cave, three pictographs were dated in 1997 through plasma-chemical extraction and accelerator mass spectrometry (AMS). The resulting four dates were reported in American Antiquity (Diaz-Granados et al. 2001:66, 481–493) and produced a weighted average of cal AD 1025. Charcoal pigment removed a few years later from a...

Although the InnovX Alpha Series portable X-ray fluorescence device we used to qualitatively analyze ceramics pigments and Lowry Pueblo Kiva white paint repeatedly reported As (in hundreds of measurements) whenever significant amounts of Pb were present, there were in fact no significant amounts of As present in those samples. Obviously, care must...

This paper investigates the potential for identifying and dating black pigments in the Formative-style (800-400 B.C.E.) murals at Oxtotitlán Cave, Guerrero, Mexico, with the goal of studying prehistoric paint technology and the socio-political context of early Mesoamerican art. These murals are among the earliest in Mexico, if not the earliest, and...

The petroglyph site in Jabal Jassasiyah Qatar is located approximately 60 km northeast of the capital city of Doha and has over 900 different types of petroglyphs. The most commonly found petroglyphs are cupules, which are almost always arranged in geometric patterns. A number of petroglyphs of boats are also found, usually seen from above, with a...

We have measured the abundance and isotopic composition of xenon in petroleum samples from the Shell Bullwinkle Field off the coast of Louisiana. We used an oxidation and purification procedure designed to insure complete extraction and clean up of xenon from the petroleum. The xenon isotopic composition was found to be similar to the atmospheric...

One always enters rock art sites equipped with a very sensitive, perceptive instrument: human eyes. This tool has permitted much fundamental understanding of rock art. Over the past decade or so, portable X-ray fluorescence (pXRF) devices have become more available as nondestructive field instruments. By measuring the presence of metallic elements...

A technique based on cold argon and oxygen plasmas permits radiocarbon dates to be obtained on paintings that contain inorganic pigments. (To listen to a podcast about this feature, please go to the Analytical Chemistry website at http://pubs.acs.org/journal/ancham.).

We present data using plasma-chemical extraction, originally developed to 14C date rock paintings, for virtually 'non-destructive' 14C dates from perishable artifacts. No visible alterations were observed in test samples after enough carbon was collected for both an AMS 14C date and a stable isotope measurement. With many subsequent plasma reaction...

An unsuccessful attempt to study ancient DNA from Pecos River genre rock paintings located in shelter 41VV75 in the Lower Pecos River region of southwest Texas is described. We were unable to extract any ancient DNA from these Pecos River genre rock paintings, casting doubt on a previous study that reported extraction and characterization of ancien...

Samples from three charcoal pictographs at Ignatievskaya Cave, in the southern Ural Mountains of Russia, have been radiocarbon dated. An advanced antiquity was expected, with some paintings thought to be more than 10,000 years old, as suggested by the imagery. One charcoal painting, for example, resembles a mammoth. The radiocarbon date of that mot...

A sample from a charcoal rock painting at the Arnold/Tainter Cave site (47Cr560) was radiocarbon dated, providing the first direct age determination for a pictograph in Wis consin. The sample was pretreated with HCl and NaOH before organic carbon was ex tracted using an oxygen plasma. The painting, of a creature resembling a caribou because of the...

Abstract— Elemental and isotopic compositions of the noble gases have been determined in six North American tektites (4 bediasites and 2 georgiaites) and one Ivory Coast tektite. Radiogenically produced 4He may explain the large 4He/36Ar ratios measured relative to air, despite significant diffusive losses. The Ne isotopic composition is enriched i...

The source of binder/vehicle(s) used by prehistoric North American artists to prepare their paints was previously unknown. Little DNA is expected to survive after several millennia; but even minute quantities of degraded DNA can be amplified by polymerase chain reaction and sequenced. An ancient fragment of pictograph histone DNA from two ca. 3,000...

We have characterized round phyllosilicate aggregates in Orgueil and Al Rais, and conclude that they formed from aqueous alteration of glassy spheres.

Three to four thousand year old DNA in Pecos River style pictographs was subjected to polymerase chain reaction (PCR) amplification and phylogenetic analysis. We sequenced a 106 base-pair (bp) fragment from the highly conservative histone 4 gene, assessing potential contamination by using negative controls (no DNA) and positive controls (known DNA)...

Direct radiocarbon dating of pictographs has recently become possible. The authors report here the deleterious effects on such dating of hydrocarbon contamination of a pictograph in southeastern Utah. In order to enhance contrast between a pictograph and its rock substrate, some photographers have wetted pictographs with kerosene or similar substan...

We have dated a sample of red paint taken near an anthropomorphic pictograph in Elk Creek Cave in the Pryor Mountains, Montana. The radiocarbon date obtained, 840±50 years BP, is in agreement with expectations based on archaeological inforence.

Controversy has surrounded the All American Man pictograph in southeast Utah since its discovery in the 1950s. Its coloration, similar to the flag of the United States of America, has led to questions regarding its authenticity. We have obtained two radiocarbon values on a single sample comprised of pigmented sandstone fragments from one small area...

In 14 C dating of pictographs, we use a low-temperature oxygen plasma coupled with high-vacuum techniques to selectively remove carbon-containing material in the paint without contamination from the rock substrate, even if limestone (CaCO 3 ). In addition to one previously published measurement, we analyzed two more pictograph samples, which are in...

We have developed a new statically operated oxygen plasma method that allows direct14C dates to be obtained from ancient rock paintings. The method is applicable even to paintings on limestone (CaCO3) walls. A sample of a pictograph which had naturally spalled offa shelter wall in the Lower Pecos region of Texas was subjected to a low temperature (...

We have constructed an inexpensive computer-assisted thermogravimetric/magnetic balance utilizing a Cahn TA450 electronic analytical balance and an Apple II + personal computer, both of which were already available in an undergraduate laboratory. Some details of the hardware and software interfacing necessary to make the apparatus work are presente...

Pulsed laser, single-color, (2 + 1) multiphoton ionization is used to achieve elemental selectivity while concurrently eliminating isobaric interferences for lead (Pb) and bismuth (Bi) mixtures detected via resonance ionization mass spectrometry. Experimental results are compared with theoretical calculations by using a simple rate equation formali...

Theory and results are presented for Resonance Ionization Mass Spectroscopy (RIMS) diagnostics of a variety of laser-materials interactions.

An equation relating the calorific values of lignites to their proximate analyses (% moisture, % ash, % volatile matter, and % fixed carbon) is presented. Equations based on proximate analysis have been developed for higher ranks of coal, but not for lignite.Our equation was determined by least squares fitting using matrix algebra. Gauss reduction...

Three small samples of the Odessa, Texas iron meteorite, two surrounded by sandy soil, were introduced into a hydrogen plasma. The soil was effectively cleansed from the iron surfaces, being substantially destroyed with only a fine dust remaining. The appearance of the iron meteorite samples indicated that the terrestrial oxidation was reversed, pr...

A fascinating article which dates the formation of the elements and reveals an overview of the methodologies to do so. Keywords (Domain): Physical Chemistry

The saturation magnetization of some carbonaceous chondrites was studied using a Faraday balance. The authors present measurements on the magnetite contents of some CM2, CV3 and a CV5 chondrites. The method was also used to measure the content of metallic nickel-iron in Ornans, 3.4±0.3%. Of the CM2 chondrites examined, only Bells, Essebi and Haripu...

The discovery of radioactivity, radioactive dating, and various dating methods. Keywords (Audience): High School / Introductory Chemistry

The use of thermomagnetogravimetry has been proposed as an alternative to the ASTM methods for measuring the pyritic sulphur content of coal and for proximate analysis. This paper presents a comparison of the results of thermogravimetry for proximate analysis and thermomagnetometry for pyritic sulphur with ASTM values on the same samples. The therm...

Many of the unusual magnetite morphologies previously observed only in the CI chondrites have been seen in the CM chondrites, Essebi and Haripura. These include: heavily textured spheroids, which are possibly spherulites, found both singly and in groups of up to a dozen and ranging in size from ∼4 to 10 μm in diameter; collections of microcrystals...

Magnetite contents obtained by 939 measurements of the CI chondrites are reported, and standard statistical analyses of these data indicate the existence of two subgroups, of which one consists of Ivuna and Orgueil, and the other of Alais, Revelstone and Tonk. Since the precision of the method used is about + or - 3%, the standard deviations given...

Analysis of the water formed during isothermal reductions of single crystal fragments or sintered polycrystalline samples of Fe3O4 by H2, in the temperature range from 350 to 450 ° C, clearly demonstrated that there was no effect of an external magnetic field (6.9 kOe) upon the observed reaction rate. When powdered samples of Fe3O4 were used, howev...

We have confirmed reports by Rowe et al. indicating that a strong (4.6 kOe) magnetic field influences the rate of reduction of some cobalt and iron oxides. In addition to our earlier gravimetric methods, we simultaneously carried out an evolved gas analysis such as that described by Gallagher et al. The discrepant results may arise from differences...

A new method for measuring pyrite contents in coals and lignite combines thermogravimetry and thermomagnetometry. The pyrite contents of five samples of coal and lignite determined by this method are compared to those obtained by the ASTM method. -P.Br.

Mass spectrometric analyses of He, Ne and Ar were performed on the mesosiderites, Clover Springs, Crab Orchard, Patwar, and Hainholtz with comparative analyses also conducted on the achondrite Binda. Gases were released in incremental temperature steps so that variation of spallogenic compositions could be studied. All samples were found to be rich...

The cosmogenic xenon isotope patterns were calculated independently for each temperature fraction from Patwar and also for the Estherville mesosiderite data of KAISER and RAJAN. A distinct correlation with temperature was observed which is comparable to other results on achondrites and lunar materials. These spallation product compositional variati...

A STRONG magnetic field (500-1,400 Oe) was reported by Skorski1 to cause an increase in the reduction rate of haematite (Fe2O3) to metallic iron when H2 was used as the reducing agent. This effect was attributed to the magnetic properties of the H2, because neither CH4 nor CO produced a similar increase when under the influence of a strong magnetic...

Stacks of thin Mg, Al, Si, Ca, CaF2, Ti, and stainless steel foils were bombarded in twelve irradiations by a variable energy cyclotron. Cross sections are reported for He and Ne in natural Mg, Al, and Si, and for He in CaF2, and for Ar in natural Ca, as determined from mass spectrometer analysis of the inert gases. In addition, cross sections of N...

Some degree of correlation was noted between the thermomagnetic behavior of the carbonaceous chondrites and the chemical-petrographic classification scheme of Van Schmus and Hayes.

Results are reported for analysis of the uranium in multiple samples of each of six igneous-rock standards (dunite, granite, lujavrite, norite, pyroxenite, and syenite) prepared as geochemical reference standards for elemental and isotopic compositions. Powdered rock samples were examined by measuring delayed neutron emission after irradiation with...

Samples of all eighteen known C2 chondrites have been analyzed thermomagnetically. For eleven of these, initial Fe3O4 content is low (generally less than 1%) and the saturation magnetization-vs.-temperature curves are irreversible. The heating curves show variable and erratic behavior, whereas the cooling curves are similar to that of Fe3O4. The sa...

The parent body of the Farmington meteorite experienced sufficient heating, probably from shock accompanying a major collision occurring 520 million years ago, to erase the record of any magnetization acquired prior to that event. Therefore, the observed magnetization in the Farmington meteorite must have been acquired after the collision. Shock-pr...

CARBONACEOUS chondrites, although comprising only about 2% of known meteorites, are extremely interesting for scientific investigation. Their mineral constitution, and the correspondence between their bulk chemical composition and the solar abundance of condensable elements, indicate that minimum chemical fractionation and thermal alteration have o...

Thermomagnetic analysis was made on samples of all known C3 and C4 chondrites in a controlled oxygen atmosphere. Considerable variation was noted in the occurrence of magnetic minerals, comparable to the variation observed earlier in the C2 chondrites. Magnetite was found as the only major magnetic phase in samples of only three C3 chondrites (2–4...

An overview of this subject is presented. The paper includes a glossary of magnetism terminology and a discussion of magnetic techniques used in meteorite research. These techniques comprise thermomagnetic analysis, alternating field demagnetization, thermal demagnetization, magnetic anisotropy, low-temperature cycling, and coercive forces, with em...

Samples of all five of the known C1 chondrites have been analyzed thermomagnetically. The only magnetic phase found in four of the chondrites (Alais, Ivuna, Orgueil, Tonk) was magnetite containing less than 6% nickel. The Revelstoke C1 chondrite contains essentially Ni-free Fe3O4 as the predominant phase; however, a small amount of a thermally unst...

Latimer1 and Urey2 first investigated the oxidation states of iron in the dust phase of the solar nebula, demonstrating for the reaction that the equilibrium constant K = H2/H2O is determined by the relative abundance of hydrogen and oxygen in the solar nebula. The equilibrium constant is further related to the standard free energy change, ΔG°, by...